Differential Diagnosis for Bumps on Scalp
Single Most Likely Diagnosis
- Seborrheic keratosis: A common, benign skin growth that can appear on the scalp, often due to aging and sun exposure. It's likely due to its high prevalence and the fact that it commonly presents as a bump on the scalp.
Other Likely Diagnoses
- Folliculitis: An inflammation of the hair follicles, often caused by bacterial or fungal infections, which can present as bumps or pimples on the scalp.
- Keratosis pilaris: A harmless condition characterized by small, rough bumps on the skin, including the scalp, due to excess keratin.
- Ingrown hair: A condition where hair grows back into the skin, causing inflammation and bumps, especially in areas with curly hair.
- Cysts (such as epidermoid or pilar cysts): Benign, fluid-filled bumps that can appear on the scalp due to blocked oil glands or hair follicles.
Do Not Miss Diagnoses
- Skin cancer (such as basal cell carcinoma, squamous cell carcinoma, or melanoma): Although less common, skin cancer can present as a bump on the scalp and is critical to diagnose early due to its potential severity.
- Infectious diseases (such as ringworm or impetigo): Contagious conditions that can cause bumps, redness, and other symptoms on the scalp, requiring prompt treatment to prevent spread.
- Lymphoma: A type of cancer that can cause bumps or masses on the scalp, particularly in individuals with weakened immune systems.
Rare Diagnoses
- Dermatofibroma: A rare, benign skin growth that can appear as a bump on the scalp, often resulting from minor injury or insect bites.
- Sarcoidosis: A condition characterized by the growth of granulomas (inflammatory cells) in various parts of the body, including the scalp, which can cause bumps or lesions.
- Cutaneous metastasis: A rare occurrence where cancer from another part of the body spreads to the skin, including the scalp, presenting as a bump or nodule.